Loop antenna



June 10y 1930. A F. VAN DYcK 1,763,38?

OOOOOOOOO NA June 10, 1930. A. F. vAN DYcK LOOP ANTENNA Filed Sept. 19, 1925 2 SheetS-Shet 2 NvENToR ARTHUR F. VANDYCK Patented June 10, 1930 UNITED STATES PATENT OFFICE ARTHUR F. 'VAN DYCK, OF YONKERS, NEW YORK, ASSIGNOR. 'I'O RADIO CORPORATION OF AMERICA, A CORPORATION OF DELAWARE LOOP ANTENNA Application flled September My invention relates to a loop antenna and particularly to antennae adapted 'to utilization with a portable radio receiving set.

An object of my invention is to provide a portable radio receiving set having a lid which is adapted to serve simultaneously as a support for a loop antenna and as a protective cover for the control of a radio receiving apparatus.

Another object of my invention is to provide a compact pivoted loop antenna adapted to cooperate with a radio receiving apparatus.

Another object of my invention is to provide a loop antenna Which may be used alternatively as a freely swinging pivoted structure or clamped to a portion of the case containing the radio detector.

Another object of my invention is to provide a pivoted loop antenna which shall bevstructurally rugged and protected against ury.

Another object of my invention is to provide a pivoted antenna structure Within a protecting case which is adapted alternatively to function as a protecting lid for a radio detector, or as a freely swinging directive antenna.

Another object of my invention is to provide a portable radio receiving set having means whereby it may be conveniently transported while operative and receiving signals.

Another object of my invention is to provide a radio receiving device having 'a loop antenna which is adapted to protect the controls while the device is transported in an inoperative condition and is further adapted to be attached in a convenient position Whereby it may function when the device is transported in an operative condition.

Another object of my invention is to pro-` vide a swinging loop antenna mounted on a swinging door and frame wihch shall have no variometer characteristics.

Another object of my invention is to provide a swinging loop antenna revolvable about two separate axes which may be revolved Without changing the inductance thereof.

In the construction of portable receiving apparatus, difiiculty has been experienced in providing a suitable antenna structure.

19, 1925. Serial No. 57,339.

My invention provides a loop antenna whch is conveniently operable, which is adequately protected against accidental mechanical injury, which is pleasing in appearance, which serves alternatively as a protection for the controls of the radio apparatus and Which may be dismounted from its pivots and attached to the rear of the cabinet in a fixed position When signals from a given direction only, are desired. l/Vhen so attached to the rear of the cabinet the loop antenna is in a position which puts it conveniently out of the Way While still being in operative condition. It thus permits convenient transportation of the device Without imposing the necessity of rendering the device inoperative by disconnecting the current source and closing the front cover.

Other objects and structural details of my invention will be apparent from the following description when read in connection with the accompanying drawing wherein:

Fig. l is a view in perspective of the front elevation of an embodinent of my invention Fig. 2 is a rear elevation in perspective of the same embodiment, v

Fig. 3 is a view partly in section of the loop antenna and pivot structure of my invention,

Fig. 4 is a vertical section of the loop antenna along the lines IV-IV of Fig. 3,

Fig. 5 is a view partly in section of the cabinet of my invention and the loop antenna attached thereto,

Fig. 6 is a view of case contact members of my invention, and

Fig. 7 is a view of contact brush and pivot members of my invention.

Referring to the paragraph referring to the figures, my invention provides a cabinet l adapted to contain batteries (not shown) and the tubes and circuits of a radio detector system having tuning control knobs 2 and 3 and indicating dials 4 and 5, a rheostat control knob 6 and volume control knob 7. The case l is further adapted to house a loud speaker Which is protected by a fretwork panel 8.

To the cabinet 1 are attached hinges 9, which, in turn, support the rectangular frame A the panel 16 being desirably attached by screws to the frame 15.

The loop antenna structure 14 s supported within the frame 11 by ivots 18 and 19, best seen in Figs. 3 and 4. 'Ilhe pivot devices may consist of a point portion and a socket portion 3 and 4. The

as shown in the section in Fi pivot member 18 is desrably threaded through the frame 11 in order that t may conveniently be withdrawn to permit the removal of the antenna structure 14 from the frame 11.

The coil of wire forming the antenna crcuit is indicated at 21 in Fig. 3. One end of the loop antenna structure is attached to the cup member of pivot 19. Connection is made by a wire 22 from the point member of 19 to one on the hinges 9 and from the hinge to the radio detector system within the cabinet 1. The point member of pivot 19 is surrounded and supported by an msulating member 23 which is furtherl surrounded by metal cup member 24 which is attached by a wire 25 to another of the hinges 9. A brush assembly 26, better shown in Fig. 7, cooperates with the contact member 24. The other end of the loop winding 21 is attached to the brush member 26. The final end of the winding 21 of loop antenna is attached by a wire 27 to the cup member of pivot 18.

An obvious mechanical construction for making connection to the conductor 21 would be by connection to the respective pivots 18 and 19 with wires leading from the bottom pivot to the bottom hinge 9 and from the top pivot to the hinge 9.l Such a construction, however, has a serious disadvantage, that it would provide a turn of wire integral with the frame 11 which would not rotate when the winding 21 was rotated. In consequence, when the plane of the coil 21 was positioned parallel to the frame 11,'and such single turn of conductor, a given inductance would be obtained. By rotating the frame 11 by 180 the direction of winding of the respective coils would be reversed, thereby producing a change in the inductance of the loop, by an operation in which it is essential for satisfactory reception that no change in inductance occur. This difliculty is avoided by. bringingboth of the conductor leads from the loop winding 21 to the conductor circuits at a single pivot as previously described thus avoiding the variometer effect just described.

Contact members 28 and 29 are further provided and are threaded into the cup members of the pivots 18 and 19 and make electrical contact thereto.

Socket plates 31 and 32 are attached to the rear of the cabinet 1. These socket plates are adapted to cooperate with the contact members 28 and 29 to support the antenna structure upon the rear of the cabinet 1. Electrical connection is then made to the contact members 28 and 29 by spring contactors 33 1'which are better shown in perspective in This structure functions in several ways. The frame 11 may be closed against the front of the cabinet 1 with the antenna structure 14 in place and the whole then functions as a lid to protect the knobs 2, 3, 6 and 7, and indicators 4 and 5 and the fretwork front 8 of the loud speaker.

The receiver apparatus may be placed in operation by opening the frame 11, and with it the antenna panel 14. The set may be energized by a movement of the rheostat knob 6 and the` receiving circuits tuned to the desired wave length by means of the knobs 2 and 3. The frame 11 may be swung aside into any convenient position and the loop antenna structure 14 is then free to be swung into the plane parallel to the direction of propagation of the desired signals. up by the coil 21 is then transferred by way of the pivot 19, wire 22 and one of the hinges 9 to the circuits of the radio detector and the circuit is completed from the coil 21 by way of the brush member 26, the contact ring 24, the wire 25 and another ofthe hinges 9 to the detect-or. circuits.

In the event that the desired signals are received in a plane substantially parallel with the front of the cabinet 1, the loop antenna structure 14 may be removed from the frame 11 by loosening the point member of the pivot 18. The antenna structure 14 may then be positioned upon the rear of the cabinet 1 and held in place by the socket plate members 31 and 32. Connection is then made from the antenna winding 21 through the pivot members 18 and 19, the wire 22, the contact members 28 and 29 and the contact fingers 33 to the receiving circuits of the detector and the frame then functions in the usual manner.

dBy this construct-ion, I produce a very convenient portable radio receiving apparatus in which the loop antenna structure is freely mounted upon two parallel axes whereby it may be placed into an may be swung aside the radio detector.

My invention further provides a loop antenna which may be attached to the rear of the receiver cabinet.

While I have shown but a single embodiment of my invention, it is ca able of various modifications therefrom an it is desired therefor that only such limitations shall be rom the controls of Signal energy picked.

vertical plane and imposed thereon as are required by the art or indicated in the appended claims.

I claim- 1. A radio cabinet adapted to house a radio detector circuit, a lid therefor havinga pivotally mounted panel, adapted to protect said detector, to house a loop antenna, andto be swung with said antenna into a planecooperating with radio signals, and means for removing said panel from said lid and means for attaching said panel when removed from said lid to said cabinet in a fixed position and simultaneously making in said fixed position electric connection with said detector.

2. A radio system, comprising a cabinet, a detector therein, a loop antenna, an open frame hinged to the cabinet having supporting pivots for said antenna, a contact collar around one' of said pivots, a contact brush cooperating With said collar connections from said' pivot and said collar to said detector and connections from said loop antenna to said last mentioned pivotand to said collar.

3. A radio system comprising a cabinet; a radio receiver; a loop antenna; a frame encircling the loop; supporting pivots for removably and rotatably mounting said anprior tenna in said frame; a contact collar around one of said pivots; a contact brush cooperating with said collar; connectionsv from said loop antenna to said collar and to said pivot encircled by said collar; connections from said encircled pivot and collar to said receiver; socket members attached to said cabinet; cooperating hook members attached to said antenna; and conductors from said socket members to said receiver for connect ing said loop to said receiver When said hook members are caused to engage with said socket members.

4. Radio receiving apparatus comprising a loop antenna; a support therefor; an intermediate frame hinged to the support, coinpletely encircling and pivotally supportang said loop; and means comprisng connections adjacent one of said pivots for said loop antenna for maintaining the inductance of said antenna substatially constant during rotation thereof.

5. A radio system comprising a supporting cabinet, an intermediate pivotally mounted supporting frame, a protected antenna coil pivoted therein and completely encircled thereby, and means conprising parallel conductor members cooperating with a single pivot between said protected coil and said intermediate frame Whereby change of inductance with rotation to said loop coil is avoided.

6. In apparatus of the character described a loop antenna removably and pivotally mounted at its central axis to a frame encircling said antenna, a connection from said antenna to a pivot on said frame, a second connection from said loop to a collar, on the frame, insulated from and encrcling said pivot, and a cabinet hingeably supporting said frame.

ARTHUR F. VAN DYCK.

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